Regarding that honking sound it is definitely coming from the CCV however it doesnt mean it is shot. Last winter I heard that noise a couple times when the temps got down in the 20's. Since I had just bought the car I decided to do the CCV anyway later that spring. The CCV I took out appeared to be only a couple years old at best and seemed to be functioning fine.

One thing you might want to check though is to make sure the oil dipstick drain tube is not clogged. Better yet you might want to replace the dipstick with the Cold Climate model that allows for better drainage into the oil pan.

Cold Climate Dipstick Part Number: 11437563831

Cold climate version dipstick guide tube, a common upgrade over the standard guide tube

This cold weather dipstick guide tube has been designed for colder environments and to prevent oil caking inside the guide tube. Commonly the oil traveling through the oil separator hose at the bottom of the dipstick can condense when cold causing blockages. When replacing the PCV system in your X5 it is also worthwhile to inspect the guide tube and to replace if it is clogged up.